1. Field of the Invention
The present invention relates to an inductor element provided on an insulating substrate, and an inductor bridge and a high-frequency filter that include the inductor element.
2. Description of the Related Art
Hitherto, there has been a demand to reduce the thickness of various components to be provided in a circuit in thin and small electronic devices such as portable terminals. In addition, it has been required to elaborate the shape of various elements in order to dispose the various elements in a limited space.
A common inductor element is formed as a chip inductor to be mounted on a circuit substrate, or incorporated into a circuit by forming a conductor pattern of an inductor on a circuit substrate. For example, International Publication No. 2010/016345 teaches a multilayer inductor that includes a plurality of insulating layers having a coil formed from a conductor pattern.
While it is possible to reduce the size of a chip inductor and a pattern inductor by forming finer conductor patterns or by forming conductor patterns in a multiplicity of layers, such a size reduction involves the following issues.
The direct-current resistance (DCR) is increased along with a reduction in line width of the conductor patterns.
An increase in interline capacitance and interlayer capacitance increases the floating capacitance per obtained inductance, which lowers the self-resonant frequency. Thus, the frequency band that allows use as an inductor is narrowed. For example, the bandwidth that allows use as a high-frequency filter is narrowed.